1. Field of the Invention
Embodiments of the invention relates to microprocessors and microprocessor systems. In particular, at least one embodiment of the invention relates to an instruction encoding technique resulting in a compressed instruction format.
2. Description of Related Art
Microprocessor technology has evolved over the years at a fast rate. Advances in computer architecture and semiconductor technology have created many opportunities to design new processors. There are typically two options for designing new processors: (1) defining a completely new architecture, and (2) extending the current architecture to accommodate new features.
New processors involve new features in both hardware and software. A new processor based on existing design typically has an additional set of instructions that can take advantage of the new hardware design. However, extending an instruction set by adding a new set of instructions is a challenging problem because of the constraints in the encoding of the instructions and in storing instruction opcode maps. Therefore there is a need in the industry to provide an efficient method for extending an instruction set without increasing hardware complexity and without significantly expanding the number and size of opcode maps.